如何从字节数组创建图像并显示？

Question

I want to get data from an image file and display that information in a texture that Unity can read.

I am able to get the pixel information into a byte array, but nothing ever displays on the screen. How do I actually get the image to display?

     pcxFile = File.ReadAllBytes("Assets/5_ImageParser/bagit_icon.pcx");
     int startPoint = 128;
     int height = 152; 
     int width = 152; 
     target = new Texture2D(height, width);
     for (var y = 0; y < height; y++)
     {
         for (var x = 0; x < width; x++)
         {
             timesDone ++;
             pixels[x, y] = new Color(pcxFile[startPoint], pcxFile[startPoint+1], pcxFile[startPoint+2]);
             startPoint += 4;
             target.SetPixel(x, y, pixels[x, y]);
         }            
     }
     target.Apply();
     target.EncodeToJPG();

Answer 1

Well, (assuming you get the pixel data correctly) you have to asign that created texture to something...

I'ld use eg a RawImage since it doesn't need a Sprite (as the UI.Image component would do - also see the RawImage Manual ):

// Reference this in the Inspector
public RawImage image;

//...

pcxFile = File.ReadAllBytes("Assets/5_ImageParser/bagit_icon.pcx");
int startPoint = 128;
int height = 152; 
int width = 152; 
target = new Texture2D(height, width);
for (var y = 0; y < height; y++)
{
    for (var x = 0; x < width; x++)
    {
        timesDone ++;
        pixels[x, y] = new Color(pcxFile[startPoint], pcxFile[startPoint+1], pcxFile[startPoint+2]);
        startPoint += 4;
        target.SetPixel(x, y, pixels[x, y]);
    }            
}
target.Apply();
// You don't need this. Only if you are also going to save it locally
// as an actual *.jpg file or if you are going to
// e.g. upload it later via http POST
//
// In this case however you would have to asign the result 
// to a variable in order to use it later
//var rawJpgBytes = target.EncodeToJPG();

// Assign the texture to the RawImage component
image.texture = target;

Alternatively for using with normal Image component create a Sprite from your texture using Sprite.Create :

// Reference this in the Inspector
public Image image;

// ...

var sprite = Sprite.Create(target, new Rect(0.0f, 0.0f, target.width, target.height), new Vector2(0.5f, 0.5f), 100.0f);

image.sprite = sprite;

---

Hint 1
In order to have the correct aspect ratio I used a little trick usually:

1. Create a parent object for this RawImage
2. Set the desired "maximal size" in the RectTransform of the parent
3. Next to the RawImage / Image (on the child object) add an AspectRatioFitter (also see the AspectRatioFitter Manual ) and set AspectMode to FitInParent .

4. Now in the code adjust the aspect ratio (you get it from the texture):

    public RawImage image; public AspectRatioFitter fitter; //... image.texture = target; var ratio = target.width / target.height; fitter.aspectRatio = ratio; 

---

Hint 2
It is "cheaper" to call SetPixels once for all pixels than calling SetPixel repeatedly:

// ...

startPoint = 0;
pixels = new Color[width * height]();
for(int i = 0; i < pixels.Length; i++)
{
    pixels[i] = new Color(pcxFile[startPoint], pcxFile[startPoint+1], pcxFile[startPoint+2]);
    startPoint += 4;
}

target.SetPixels(pixels);
target.Apply();

// ...

(I don't know how exactly your pcx format works but maybe you could even use LoadRawTextureData